1. Field of the Invention
The invention concerns a turbine system for utilizing oceanic waves and for converting the energy contained in such into electrical energy.
2. Description of the Related Art
Such systems became known, for example, in EP 0 000 441 A1 and GB 2 250 321 A.
Systems of this type are designed as follows: They include a chamber that is open at its lower end and this open end is submerged into the ocean. At its upper end, the chamber also has an opening. Further, a duct is provided that serves to guide a stream of air. At its open end, the duct is connected to the upper opening of the chamber. Inside the duct, an energy unit is located that is enclosed by it and which is coaxially mounted to the duct with a turbine rotor, as well as perhaps with an electrical generator that is in drive connection with the rotor.
The level of ocean water within the chamber rises and falls continually as a result of the oceanic waves; the movement of these waves thus acts into the chamber. Inherent in each rise of the water level, a displacement of the amount of air that is in the chamber takes place. Air is displaced when the water level rises and flows through the upper opening of the chamber and thus also through the duct in which the turbine is mounted. The stream of air drives the turbine and thereby also the electrical generator that, as such, generates electrical energy.
When the water level falls, the same process takes place in the chamber—only the stream of air reverses itself. Mechanical possibilities exist for letting the turbine rotor run in one and the same rotational direction, regardless of the direction of the stream of air. Such a possibility is described, for example, in GB 1 595 700 B.
The wave energy that is contained in the oceans of the world in inexhaustible. The median annual wave energy at a depth of 10 m is at a range of magnitude of 10 kW/m, and at a depth of 40 m, at 50 kW/m. The problem lies, however, in an economic utilization of the abundantly present energy, so that the costs per Kilowatt hour are competitive. To convert such into economically usable energy at acceptable costs is, however, often not possible in many systems that convert renewable energies as they are provided by nature. The economics of a system of the type described thus often heavily depends on the degree of effectiveness. The possibilities of exerting an influence are limited.
What is needed in the art are systems of the type mentioned at the beginning which are improved such that their degree of effectiveness is increased.